code: def test_val_process(self):
      self._metric.train()
      _state = self._state.copy()
      _state[torchbearer.Y_TRUE] = _state[torchbearer.Y_TRUE][0]
      result = self._metric.process_validate(_state)
      for i in range(0, len(self._targets)):
          self.assertEqual(
              result[i],
              self._true_targets[i],
              msg="returned: "
              + str(result[i])
              + " expected: "
              + str(self._targets[i])
              + " in: "
              + str(result),
          )
  
file_path: torchbearer/tests/callbacks/test_mixup.py
imports: from unittest import TestCase
  from mock import patch, call, MagicMock
  import torch
  import torchbearer
  from torchbearer.callbacks import Mixup, MixupAcc
label_desc: Use image node_id 3 for calling the TestMixupAcc obj's underlying member method code with example usage: obj.test_val_process() without return types